Seismic safety valve and valve actuator

ABSTRACT

A safety valve is positioned in supply plumbing that supplies a fluid medium such as natural gas to a point of use structure such as a home. A mechanical actuator is provided remote from the safety valve but mechanically connected to the safety valve. This allows the actuator to be positioned, for example, directly on the point of use structure, avoiding the need for separate bracing for the valve. The valve can be provided with a tee fitting or can be a separate gate valve. The mechanical actuator can be actuated by seismic disturbance, manually, or by activation by remote sensor or home security system.

REFERENCE TO RELATED APPLICATIONS

This application is a Continuation-In-Part of International ApplicationNo. PCT/US2004/038873, filed Nov. 22, 2004, which in turn claims benefitof priority under 35 U.S.C. §119 to prior Provisional Application Ser.No. 60/523,320, filed Nov. 20, 2003.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present application relates to seismic safety valves and a valveactuator therefor. In particular, it relates to valves used to shutoffthe supply of gas to a structure in the event of an earthquake and howsuch valves are actuated.

2. State of the Prior Art

Various devices have been known in the prior art for shutting off gassystems in the event of a seismic disturbance. For example, U.S. Pat.Nos. 4,311,171, 4,565,208, and 4,475,565 all illustrate different typesof valves designed to shutoff the flow of gas in the event of a seismicdisturbance.

Applicant's own prior valves and systems include those in U.S. Pat. Nos.4,903,720, 5,119,841, 5,409,031, 6,085,772 and 6,705,340. Thesedifferent patents address various concerns with respect to shutting offthe flow of natural gas to a point of use in the event of a seismicdisturbance. These patents also recognize that other disturbances mightbe appropriate in triggering the shutoff of gas. They have in common theconcept of shutting off the flow of gas exterior to the point of usestructure. For example, the shutoff valve may be positioned at or nearthe gas meter on the exterior of the point of use structure.

The present inventor has recognized, however, that in some prior valveinstallations that are currently on the market, a number of problemsexist. For example, in prior valves, the sensor mechanism that detectsseismic activity to trigger the shutoff of the valve is incorporatedwith the valve itself. This then requires the valve to be level. Itfurther requires the valve itself to be braced to the structure, i.e. tobe directly fixed with the structure that is the point of use, forproper sensing of the seismic activity. This requires rigid bracing tobe provided, which increases the likelihood of the piping breakingbefore the valve in the event of seismic activity. The labor cost isthus high in the installation of the valve.

Prior art valves also require additional fittings to be installed, arenot adaptable to “smart” controls, and are limited to the earthquakemarket only. Further, they will not work with water. The meter usuallyneeds to be displaced for the installation, and the valve structureitself often results in poor flow of the gas.

Additionally, the present inventor has recognized that the prior artvalves do not have such desirable features as a manual shutoff. Theyalso lack a positive “off”; in other words, the valve can reset byitself after shutting off. The status indicators of the prior art valvesalso tend to be hard to read, and there tend to be too many falsetriggers of the valve.

SUMMARY OF THE INVENTION

Accordingly, the object of the present invention is to provide a seismicsafety valve and an actuator for the valve that addresses the aboveproblems recognized with the prior art. In particular, the objects ofthe invention are to reduce cost, reduce installation time, and reducethe amount of space required for the installation. A particular objectof the invention is to provide a valve arrangement in which bracing willnot be required, as with the prior art. Further objects of the inventionare to ensure a full flow of gas through the valve, to make the valveadaptable to smart controls and thus more usable with different types ofsystems on the market, and to have the valve work for water.

Further objects of the present invention are to provide a valvearrangement that can be readily expanded to different sizes fordifferent types of installations, to provide a valve with an easy toread status indicator, which can have a remote status option, and toprovide a valve in which positive shutoff of the valve results so thatthe valve will not reset by itself.

The above objects according to the present invention are achieved by avalve arrangement in which a safety valve is located in supply plumbingused for supplying a fluid medium to a point of use structure. Amechanical actuator to actuate the safety valve is mechanicallyconnected to the safety valve and located remotely from the safetyvalve. The mechanical actuator is preferably fixed to the point of usestructure and connected to the safety valve by a flexible cable. Thevalve is spring biased toward a closed position but held in an openposition by the flexible cable. The mechanical actuator holds the cablein a retracted position which corresponds to the open position of thesafety valve, and can be actuated to release the cable so that thesafety valve closes.

The supply plumbing can include a tee, with the safety valve located inthe tee. The tee has three openings, and the valve is mounted in one ofthe openings, with an inlet and an outlet for the fluid being formed bythe other two of the openings. The valve member is held in an openposition by the mechanical actuator, and a spring biases the valvemember toward a closed position in which the outlet is closed off fromthe inlet. An actuator housing is connected to the tee opening, with avalve member being mounted at an interior end of the actuated housingand the spring being housed within the actuator housing, the flexiblecable being connected to the valve member.

The supply plumbing could alternatively be two supply pipes withrespective pipe ends between which the safety valve is provided. In thisinstance, the safety valve preferably comprises a gate valve. The gatevalve includes a gate valve housing and a gate in the housing held inthe open position by the mechanical actuator and a spring biasing thegate toward the closed position, in which position the two supply pipesare closed off from each other. The gate valve housing has an inner sealand an outer seal surrounding a fluid flow passage. The gate is slidablebetween the seals to a position in which the fluid flow passage isclosed.

According to a particularly advantageous aspect of the presentinvention, the gate valve housing is connected to the two supply pipesby respective connection arrangements each comprising a union nutthreaded to the gate valve housing, an insert that engages the union nutand threads on the supply pipes engaging the respective inserts. Eachunion nut is threaded to the gate valve housing and a gate valve housingside of the union nut, and has a flange that engages an insert flange onthe insert on a supply pipe side of the union nut. The insert isthreaded to the threads of the pipe on a gate valve housing side of theinsert. This arrangement minimizes the space between the ends of therespective supply pipes by reducing the amount of space taken up by theconnections.

The mechanical actuator comprises a cable holder that is operable tohold the flexible cable in a valve open position and a cable releasemechanism that is operable to release the cable holder from holding theflexible cable in the open position so as to allow the safety valve toclose. The cable holder is preferably a movable member that is held by adetent so as to hold the flexible cable in the valve open position. Thecable release mechanism is operable to release the movable member frombeing held by the detent. The detent comprises a detent member that isheld in place by a lever to hold the movable member. The cable releasemechanism comprises a releasable latch that is operable first to holdthe lever in place so as to hold the movable member, and second torelease the lever.

The cable release mechanism preferably includes a sensor and a latchrelease that is operable to release the latch in response to activationof the sensor. A manual off trigger is also preferably provided in orderto manually operate the latch and close the safety valve. The manualtrigger is connected with a solenoid coil so that it can also beremotely operable in response to an electronic signal.

The sensor preferably comprises a ball movable in response to seismicactivity and a flapper that is activated in response to movement of theball so as to engage and release the latch. The movable memberpreferably has a cam member which can engage and reset the flapper andthe ball upon movement of the movable member after it is released frombeing held by the detent.

The detent member can comprise a locking lever that engages with thelocking surface of a housing of the mechanical actuator. Alternatively,the detent member can be a protrusion on the lever that engages with alocking surface of a housing of the mechanical actuator. As a furtheralternative, the detent member can include a ball that is held in placeby the lever so as to hold the movable member by engagement with a fixedpart of the mechanical actuator.

The mechanical actuator also preferably has a reset handle that isconnected with the movable member and is operable to reset the movablemember so as to be held by the detent. This pulls the valve memberagainst its bias with the flexible cable to the valve open position.Preferably the movable member is a rotatable hub and the reset handle isconnected with this hub. According to a further preferred feature of theinvention, the reset handle preferably has an off or on indicator on it,is rotatable with the hub, and covers the other of the off or onindicator in one of its set positions, i.e. either the closed positionor the open position, so as to be able to indicate the status of thevalve.

According to the above invention, by having the mechanical actuatorremote from the safety valve itself, the safety valve does not need tobe braced with respect to the point of use structure. This reduces theinstallation time, and eliminates the necessity for bracing. Forexample, the actuator housing can be directly mounted on the point ofuse structure without the need for any bracing and without the need forthe installation time required for such additional bracing.

By either using the service tee for the valve, or by using a gate valvewhich takes up a very small amount of space, the amount of spacerequired for the valve can be reduced. Further, by either using theservice tee or the gate valve which does not change the direction offlow or reduce the flow passage, a full flow of gas is ensured throughthe valve. The valve is adaptable to “smart” controls by beingresponsive to an outside electronic signal to shutoff, even though thevalve itself is basically mechanical. This allows the valve to be usedwith more modern integrated control and security systems for homes andother structures.

Further, the mechanical actuator according to the present invention canbe used together with safety valves of various sizes. That is, theactuator itself is not dependent upon the size of the valve that is usedwith it.

The present invention further provides an easy to read status indicator.The valve according to the invention also provides a positive offposition that will not reset by itself in view of the biasing of thevalve member to the closed position and the holding of the mechanicalactuator in such position until positively reset.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and further aspects of the present invention will become clearfrom the following detailed description of preferred embodiments of theinvention, taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a schematic view of a safety valve and valve actuatoremploying a “tee valve”;

FIG. 2 is a view similar to FIG. 1 with a cover of the valve actuatorremoved;

FIG. 3 is a view similar to FIGS. 1 and 2 showing the inside of thevalve and the valve actuator in an un-triggered valve ON position;

FIG. 4 is a view similar to FIG. 3 illustrating the triggering of thevalve actuator;

FIG. 5 is a view similar to FIGS. 3 and 4 illustrating the valve andvalve actuator in the valve closed position;

FIG. 6 is a view of the valve actuator in the valve ON un-triggeredposition;

FIG. 7 is a view similar to FIG. 6 showing manual triggering of thevalve actuator;

FIG. 8 is a view similar to FIG. 3 but illustrating a gate valvealternative;

FIG. 9 is a view similar to FIG. 2 illustrating the gate valve in theOFF position;

FIG. 10 is a cross-sectional view of the gate valve and its connectionto adjacent pipes;

FIG. 11 includes an exploded perspective view of a connector arrangementfor connecting a gate valve housing to the end of a pipe, across-sectional view of the assembled connector arrangement, an end viewof the assembled connector arrangement, and a perspective view of theassembled connector arrangement;

FIG. 12 illustrates an alternative for a release mechanism of the firstembodiment in a valve open position;

FIG. 13 illustrates the release mechanism of FIG. 12 in a triggeredposition;

FIG. 14 illustrates another alternative to the release mechanism of thefirst embodiment;

FIG. 15 illustrates the release mechanism of FIG. 14 in the triggeredposition;

FIG. 16 is a schematic view of a ball detent member for purposes offorce analysis;

FIG. 17 is a schematic view of a latch and lever for purposes of forceanalysis;

FIG. 18 is a schematic view of a latch, lever, detent and stop forpurposes of force analysis;

FIG. 19 is similar to FIG. 18 and illustrates an angular modification tothe latch;

FIG. 20 is a schematic view of a portion of the latch and leveraccording to the first embodiment;

FIG. 21 is a schematic view illustrating the forces on a releasemechanism according to the first embodiment;

FIG. 22 is an exploded perspective view of a sensor and releasemechanism according to the first embodiment;

FIG. 23 is a side view, partly in cross-section, of a release mechanismsimilar to the alternative of FIG. 12;

FIG. 24 shows the release mechanism of FIG. 25 in a state immediatelyafter activation;

FIG. 25 is a perspective view of a flapper mechanism of the releasemechanism of FIG. 25;

FIG. 26 is a plan view of a latch and lever used in the releasemechanism of FIG. 25;

FIG. 27 is a cross-sectional view taken along a cross section of FIG. 28as seen from the right;

FIG. 28 is a plan view of the release mechanism of FIG. 25 with theflapper removed;

FIG. 29 is a side view of the release mechanism of FIG. 30;

FIG. 30 is a schematic illustration of a trigger arrangement for aswitch in accordance with another embodiment of the present invention inan activated position;

FIG. 31 is an illustration of the embodiment of FIG. 32 in a resetposition;

FIG. 32 is a sectional view of a valve assembly of an alternative valve;

FIG. 33 is an enlarged sectional detailed view of the assembly of FIG.32 showing operation of a bypass during resetting of the valve to anopen position;

FIG. 34 is a view similar to FIG. 33 showing a stopper beginning toopen;

FIG. 35 is an enlarged sectional view of a cable seal of the valveassembly of FIG. 32;

FIG. 36 is a sectional view of a valve assembly that could replace theby-pass tee in the gas system;

FIG. 37 is a sectional view of the valve assembly showing it in theclosed position; and

FIG. 38 is described in U.S. Pat. No. 6,705,340, incorporated herein byreference, showing a gas system and the by-pass tee and a pipe plug.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 generally illustrates a safety valve located in supply plumbingfor supplying a fluid medium to a point of use structure and amechanical actuator to actuate the safety valve. In this embodiment thesafety valve is embodied in a “tee” which includes a gas inlet 11 and agas outlet 12. As can be seen from FIG. 3, a housing 13 mounts the valvecomponents to the tee 10.

Turning back to FIG. 1, a mechanical actuator 17 is generallyillustrated and is mechanically connected to the housing 13 but locatedremotely from the safety valve. As discussed above, this allows themechanical actuator, for example, to be directly mounted on thestructure so as to avoid the need for bracing, while allowing the valveto be mounted in the supply plumbing. This avoids the need for bracingthe valve itself.

The valve includes at least valve member or stopper 20 mounted with apiston 21 and biased by a spring 22 toward the outlet 12. A valve seal19 is provided at the outlet to seal the valve closed when the stopper20 is biased by the spring 22 into contact with the seal 19. Note theillustration of FIG. 5.

The valve member 20 is restrained from closing the valve by a cable 23that is connected with the mechanical actuator 17. The cable 23, as canbe seen from FIG. 3, is connected to the valve member, extends throughthe housing 13, and through a tubing connector 14. Tubing 15 protectsthe cable between the housing 13 and the actuator 17, and connects witha further tubing connector 16 mounted on the actuator 17.

The mechanical actuator 17 is adapted to be mounted to a point of usestructure itself by, for example, directly mounting a base 25 of theactuator 17 to the housing by appropriate known means, such as bolts.This eliminates the need for bracing the valve structure as was requiredin the prior art. Current mechanical valves on the market require suchbracing because their sensing means are located in the valve itself, andare not separate from the valve.

The actuator 17, as can be seen from FIG. 1, provides a status viewer 17a for viewing the status of the valve (either ON or OFF). A statusindicator-ON symbol is provided as shown in FIGS. 1 and 2, and a statusindicator-OFF symbol 18 a is uncovered so as to be illustrated throughthe status viewer 17 a when the valve is actuated.

By locating the shutoff valve in a standard tee fitting in accordancewith this first embodiment, both installation and disassembly are madequick and simple. Installation of the valve becomes as easy asinstalling a standard tee fitting. The standard tee fitting can replacean existing elbow in a gas system, and eliminates the need foradditional fittings as with prior art devices. As can be seen from FIG.3, the valve itself provides no additional flow restriction beyond thepresence of the tee itself. With the positive shutoff of the valve,there is no chance of the valve reopening by itself after actuation. Theuse of the valve with the standard tee fitting also allows for anextremely low internal leakage to be achieved within the valve, wellbelow mandated standards.

Noting FIG. 2, the mechanical actuator includes a trigger housing 26mounted on the base 25 and housing the components of the mechanicalactuator. A trigger housing cover 26 a covers these components, while areset handle including the status indicator-ON is positioned outside ofthe trigger housing cover 26 a.

Turning now to FIG. 3, it can be seen that the cable 23 is connectedwith a rotor hub 27. The rotor hub 27 serves as a movable member which,upon triggering of the valve, is allowed to move while holding the cable23. Reference number 28 indicates a handle connection for connecting thereset handle 50, but also points out the central rotational axis of therotor hub 27.

The cable 23 is connected to the rotor hub 27 by known means. In theposition illustrated in FIG. 3, the rotor hub 27 is held in place,retracting the cable 23 and the stopper 20 against the force of spring22. Thus, in the position of FIG. 3, the rotor hub 27 serving as a cableholder for cable 23 is biased to rotate in the clockwise direction bythe force on the cable 23 from the spring 22. It is kept from rotatingby a detent so as to hold the flexible cable 23 in the valve openposition.

In this embodiment, the detent comprises a locking ball 29 which engagesbetween an edge of the rotor hub 27 and a locking plate 30 to preventmovement of the rotor hub 27. The locking ball 29 is held in place bythe presence of two spacer balls 31 and 31 a provided in a suitablechannel in the rotor hub 27. The spacer balls are in turn held in placeby the presence of lever 32. When the lever 32 releases the spacer balls31 and 31 a as shown in FIG. 4, the locking ball 29 can move to the leftas seen in FIG. 4. An angle on locking plate 30 helps to ensure that thelocking ball 29 will move toward the left, under the force generatedfrom the rotor hub 27 being pulled by the cable 23. See also thediscussion below.

A cable release mechanism is operable to release the rotor hub 27. Inthis embodiment, the cable release mechanism releases the lever 22 fromits position holding the spacer balls 31 and 31 a in place to allowmovement of the locking ball 29 and thus movement of the rotor hub 27.Thus in this embodiment, the cable release mechanism includes areleasable latch which holds lever 32 in place and is operable torelease the lever to allow movement of the rotor hub 27. The releasablelatch is designated by reference number 34. As can be seen from FIG. 4,when the latch 34 moves about latch pivot 35 to release lever 32, lever32 rotates about lever pivot 33 against the force of return spring 32 adue to the force applied by the spacer balls 31 and 31 a through theforce on the locking ball 29. The cable release mechanism furtherincludes a sensor and a latch release that is operable to release thelatch 34 in response to activation of the sensor. Interaction of thelatch and the lever is discussed in further detail below with respect tothe latch surface 36. Also note the discussion of the activation of thelocking ball 29 with respect to the vertical force and the locking balland the locking plate angle 30 a in order to have the locking ball movedto the left.

In this embodiment, the sensor is embodied by a flapper 38 which pivotson a flapper pivot 39 and carries a magnet or target 40. An inertia ball41 is mounted on a pedestal 42. In the event of a seismic disturbance ofa predetermined amount, the inertia ball 41 falls off of the pedestal 42onto the flapper 38 to pivot the flapper 38 about the flapper pivot 39into the position illustrated by FIG. 4. In this position, the flappermagnet or target 40 engages with a magnet or target 37 on the latch 34to release the lever 32. While the flapper arrangement is preferred inthis embodiment, various sensor mechanisms and ways of releasing therotor hub 27 will occur to those of skill in the art. For example,attention is directed to the various shutoff mechanisms illustrated inU.S. Pat. Nos. 6,705,340, 6,085,772, 5,409,031, 5,119,841 and 4,903,720;each of these patents is incorporated herein by reference.

Turning now to the comparison between FIGS. 4 and 5, it can be seen thatupon, for example, a seismic disturbance, the inertia ball 41 falls offof its pedestal 42 to engage the flapper 38. This causes the latch 34 tobe released as shown in FIG. 4. This causes the lever 32 to be movableagainst its return spring by the force on the locking ball 29, allowingthe rotor hub 27 to rotate in the clockwise direction. This allows thecable 23 to be pulled out of the housing 26 through the tubing 25 toallow the valve 20 to close against the seal 19. This is the conditionillustrated in FIG. 5. Thus, a closed position of the valve results,shutting off the flow of gas between the inlet 11 and the outlet 12.

During the period of rotation from the point illustrated in FIG. 4 tothat illustrated in FIG. 5, a cam surface 27 a on rotor hub 27 engageswith a flapper cam follower 38 a to push the flapper 38 back to itsoriginal position, as shown in FIG. 5. This causes the inertia ball 41to return to the pedestal 42. This condition is maintained during theclosed position of the valve by the engagement of the flapper camfollower 38 a with the outer surface 38 b of the rotor hub 27. In otherwords, further seismic disturbance while the valve is closed will notcause the flapper 38 to return to its actuator position. Rather, it willremain ready for a re-actuation after the valve is reset.

When the valve is actuated, as noted above, the reset handle 50 rotateswith the rotor hub 27 to uncover the OFF indicator 18 a as illustratedin FIG. 9, for example. The actuator 17 is reset by using the handle 50after opening an outer cover on the actuator. The rotor hub 27 is simplyrotated back in place by the handle 50 until the return spring 32 acauses the lever 32 to push the spacer balls 31 and 31 a against thelocking ball 29 and into the position where it operates as a detent asshown in FIG. 6.

A manual off button 51 is provided on top of the trigger housing 26 forpurposes of manually activating the closure of the valve. A returnspring 51 a biases the manual off button into the position illustratedin FIG. 6. The manual off button 51 is pushed against the bias of thereturn spring 51 a to push down the flapper 38 to engage with the latch34, for example by magnetic attraction between magnet or target 37 andmagnet or target 40. A solenoid coil 53 is provided around a manual offpin 52 so that the manual off feature could in fact be remotelyactivated by activation of the solenoid coil 53. The button 51 is thusmade of a material that can be attracted by magnetic force of the coilto move the push pin 52 to tip over the flapper 38. Such a solenoid coilcould be remotely activated by interconnecting it with any number offeatures, including carbon monoxide gas sensors, home security systems,etc. Thus the valve system can be adapted to not only provide seismicshutoff, manual shutoff, but also shutoff in response to any number ofemergency situations that might be involved at the point of use.

FIGS. 8-11 refer to a gate valve alternative to the tee valveillustrated in the first embodiment. While the valve, and itsinstallation, is different, the mechanical actuator 17 is substantiallythe same, as can be seen for example from the illustration of FIG. 8.

In this embodiment, a gate valve housing 60 has a fluid passageway 61therethrough for the flow of gas between pipes 70. A gate 62 is biasedby first and second gate springs 64 and 64 a toward a closed position.FIG. 8 illustrates an open position in which the gate is held in theopen position by cable 23 and actuator 17 in the same manner asdiscussed above. The cable 23 is connected to the gate 62 by a suitablecable gate connector 65. The springs 64 and 64 a are connected to thegate by spring gate connector 66 and connector pin 66 a. In thisembodiment, similar to the first embodiment, triggering of the actuator17 causes the cable 23 to be allowed to move under the bias of thesprings 64 and 64 a so as to push the gate 62 into a closed position inwhich it cuts off the fluid passageway. This position is illustrated inFIG. 9. It should be pointed out that the gate 62 is supported andallowed to float between two seals 63. Also note FIG. 10. Seal retainers63 b include grooves 63 a holding their respective seals 63. The housingprovides a stop for the movement of the gate 62 in the closed positionof the valve. The spring cylinder 67 in the gate valve housing 60 isformed for the expansion of the springs 64 and 64 a, furthermore. As canbe seen from FIG. 9, an end 62 a of the gate 62 is forced into abutmentwith the housing 60 by the springs in the closed position through theaction of the spring gate connector 66 with the gate 62.

As can be best appreciated from FIGS. 10 and 11, an advantageous aspectof the present invention is a connector arrangement which permits thegate to take up only a small amount of space in the installation, andallows it to be installed on the ends of pipes with relative ease. Thegate valve, furthermore, could be used with gas or water as the fluidmedium to be stopped.

The connector arrangement includes union nuts 71 and inserts 72 forconnection and engagement with the gate valve housing 60 and the ends ofpipes 70. In the drawing figures, reference numbers 70 a and 70 brepresent the pipe ends. The inserts 72 are threaded to the respectivepipe ends at a gate housing side of the insert; i.e. the threads on theinserts are formed at the side thereof closest to the gate housing. Theyfurther include flanges as engagement portions for engaging with theunion nuts 71 and 71 a at a pipe side of the insert, i.e. at the side ofthe insert remote from the gate housing 60. The union nuts 71 and 71 athen engage these respective flanges of the insert 72 and are threadedto corresponding gate housing union nut threads 60 a on the gate valvehousing 60. These threads on the union nuts are at the gate housing sidethereof, while their flange engages the insert flange on the insert onthe pipe side of the union nut. This arrangement, as can best be seenfrom FIG. 10, ensures that the amount of space necessary to mount thegate valve between the pipes ends 70 a and 70 b is minimized. In thedrawings, note that reference numbers 71 b and 72 c represent upper andlower union nut seals for sealing between the insert, union nut and thegate housing, as illustrated. In other words, the pipes are threadedinto the inserts so that the pipe ends are inside of the union nut, asopposed to being outside, as in normal union fittings. The ends of thepipes are thus closer together than with standard union fittings.

In the second embodiment of the valve, it should be noted that the gateis only halfway supported. That is, as can be seen from FIG. 9, the endof the gate forms a semicircle which serves to circumscribe half of thepassageway. A complete hole in the plate is not provided. This allowsthe size of the valve to be reduced, because when the gate is fullyclosed, the end of the gate sticks out less than if the gatecircumscribe the entirety of the passageway in the open position. Thisalso reduces the corresponding amount of friction during movement of thegate.

FIG. 9 also illustrates an optional plug 16 a. This simply allows thecable 23 to extend through a different location. This may be desirablewith an arrangement in which a longer amount of displacement is desired,for example with larger valves. Plus it will be appreciated that themechanical actuator can be used with valves of different sizes fordifferent situations, thus expanding the flexibility of the actuatoritself.

Turning now to FIGS. 12 and 13, a second alternative with respect to theactuator 17 is illustrated. As can be readily seen from the drawingfigure, while the rotor hub 27, latch 34 and lever 32 remain essentiallythe same as with respect to the first embodiment, the detent is formedin a different manner. The rotor hub 27 is maintained in position by theaction of a detent member engaging a portion on the housing, i.e.locking surface 82. This detent member comprises a locking lever 80which forms a detent for engagement with the locking surface on a lowerend thereof near locking lever pivot 81. Reference number 80 arepresents a lever contact point, at which point movement of the lockinglever 80 is restrained by lever 32, similar to the manner in which thelever 32 restrains movement of the spacer balls in the first embodiment.The detent engagement point, i.e. locking surface 82, as can be seenfrom the figures, is very close to the pivot point 81, and a significantmechanical advantage is provided. That is, a reduced amount of force isnecessary to hold the locking lever 80 in place, holding the rotor hub27 in place, because of the mechanical advantage. This is similar to thecase with respect to the position of the contact point 80 a with lever32.

Similar to the first embodiment, when the latch 34 is released, lever 32is allowed to move against its return spring (not illustrated in thesefigures) to allow the force at locking surface 82 to push on lockinglever 80 to allow the rotor hub 27 to rotate, allowing the valve toopen.

A second alternative is illustrated in FIGS. 14 and 15 with respect tothe actuator 17. Similar to the first alternative, in this arrangementthe spacer balls are replaced with a lever as a detent. However, in thisalternative, the lever 32 is entirely removed and substituted by asingle locking lever 90 that is held in place by the latch 34. Lockinglever detent or locking point 92 is formed adjacent locking lever pivot91 to engage with the housing. This embodiment obviously reduces thenumber of moving parts necessary. Further, spring 94, as the returnspring, can be provided with a spring return force which helps reducethe force on the latch 34 as well as acting as the return spring.Reference number 93 refers to a lever stop to prevent over rotation ofthe lever 90.

In comparing the above two alternatives with respect to the actuator 17,it should be noted that using two levers instead of one as with thefirst alternative can provide a greater mechanical advantage, due tocombining the leverage of both levers.

With respect to the first embodiment, which employs the locking ball 29,appropriate design for the proper operation of the embodiment can bedetermined in the following way.

Given vertical force on the ball, Fn, due to spring load from valve thatis transmitted by a cable, find the lateral force on the ball, Fx. Referto FIG. 16, a schematic of ball, stop and cylinder.

Fn is the input force from the spring, pulling on the cable with pullsthe cylinder onto the ball. The vertical motion of the ball is resistedby the stop with is inclined at angle α. The angled stop provides alateral force, Fx to the ball, but motion in this direction is resistedby friction of the ball against the cylinder, and is proportional to thecoefficient of friction, μ₁. ΣF in x direction and y direction=0 atincipient motion, that is dx/dt=0 & d²x/dt²=0, implies that:

Fx>Ft if the ball is to move to the left. And  1.

Fn=fy  2.

but Ft=μ₁Fn  3.

Fx=sin αFr  4.

Fr=Fy/cos α  5.

Combining Eqs. 3 and 4 into 1, we get Eq. 6; sin α Fr>μ₁ Fn. CombiningEqs. 2 and 5 into eq. 6, we get Equ. 7; μ₁<tan α. This is the conditionnecessary if the ball is to move. The coefficient of friction for steelon steel is typically between 0.25 and 0.35, depending on many factors,including contact stress, finish, lubricating materials, humidity andlength of time the materials have been in contact. In order to be surethat the ball will move when the latch is raised, the tangent of thecontact angle needs to have some reasonable margin above the highestexpected coefficient of friction. Below is a table of angles and theirtangents.

Angle, degrees Tangent 10 .176 15 .268 20 .364 25 .466 30 .577If assume an angle of 25° to be used to assure motion of the ball.Instead of an analysis of inequality to find the minimum angle toproduce motion, the same equations can be used to find the actual forcetransmitted by the ball.

Fx=Fn(tan α=μ)  Equ. 8

With respect to the first alternative, please note the followinganalysis with reference to FIG. 17, a schematic of the alternative.

The lateral force, Fx, exerted by the ball that was calculated in theabove analysis, tends to rotate the vertical lever CCW. The forceexerted by the lever onto the latch at distance b above the pivot can befound by setting the sum of the moments about the pivot to zero.

bFh=aFx  Equ. 9

If the coefficient of friction between the lever and the latch is μ₂,then the vertical force to raise the latch is:

Fy=μ₂Fh  Equ. 10 Which leads to

Fy/Fn=μ ₂ a/b(tan α−μ₁)  Equ. 11

If a=0.20, B=1.00, μ₂=0.30, μ₁=0.20 and α=25°, then

R=Fy/Fn=0.16=1.6%

If Fn=20#, then Fy=32#

A possible cost reduction change in this option is to use a smaller, sayφ.094, ball or dowel pin to provide the stop, instead of the hard steelplate. The ball or dowel pin would be inserted into a pocket molded intothe housing.

An analysis of the second alternative follows with reference to FIG. 18,a schematic of this alternative.

This is a simpler design with just three parts to the schematic. Thevertical lever is attached to the rotating hub. An extension off of thelever is restrained by a ledge on the main housing. The hub is rotatedby the force applied by the valve spring, as in Option 1, however, nowthe force, Fn, is applied to the lever extension at distance b from thelever pivot.

Fy=μ₂Fh  Equ. 12

Fh=b/aFn  Equ. 13

So that:

Fy/Fn=μ ₂ b/a  Equ. 14

If b=0.173; a=1.899, μ₂=0.30, then

R=Fy/Fn=0.27=2.7%

Both designs could benefit from the addition of a slight angle to thelip of the latch. This is discussed with respect to FIG. 19,demonstrating an angular modification to the lip of the latch. All otherforces and dimensions remain the same as with respect to FIG. 18.

Using the same kind of analysis, the force ratio for the is geometry is:

R=Fy/Fn=b/a(μ₂−tan β)  Equ. 15

When β=10°, and all the other parameters are the same as before,R=0.0113=1.13% so Fy=0.225# when Fn=20#.

FIGS. 23-29 illustrate a preferred embodiment of a variation of therelease mechanism of FIG. 12. In FIG. 23, a rotor hub 127 is illustratedwith a front cover part thereof removed, and with certain parts shown incross-section. Similar to the embodiment of FIG. 12, a locking lever 180is used to hold the rotor hub 127 in a lock position against the forceon a cable held by the rotor hub 127 in a manner similar to thepreviously-described embodiments. It is noted that parts notspecifically described with respect to this embodiment are the same aswith the previous embodiments, and the release mechanism according tothis embodiment is employed in the same way as, for example, withrespect to the embodiment of FIG. 12. Thus, a cable connected to therotor hub 127 may be spring biased by, for example, a valve membertoward a closed position of the valve, with the locking lever 180engaging a housing (not shown) to hold the rotor hub 127 in the positionillustrated in FIG. 25, similar to the operation of the embodiment ofFIG. 12.

Thus, when in a valve-open position, for example, or a lock position ofthe release mechanism of this embodiment, a locked force is applied at153 as shown by the arrow, by engagement with the rotor hub housing. Alever 132, similar to the lever 32 of the embodiment of FIG. 12, engagesan end of the locking lever 180 to hold the locking lever 180 in thelocked position of the rotor hub 127. The overall arrangement allows fora mechanical advantage of approximately 25 to 1.

The lever 132 pivots about pivot point 133, and is biased by the lockingforce 153, reduced as for example demonstrated by the arrow 154, to tendto move in the direction shown by the arrow to the left of lever 132.Thus, when the lever 132 is released, similar to the embodiment of FIG.12, locking lever 180 will be forced to pivot by the force at 153,releasing the engagement of the rotor hub 127 with the surroundinghousing and along the rotor hub 127 to rotate-under the force of thecable applied to the rotor hub 127.

Lever 132 is held in position by a latch 134. In accordance with thisembodiment, the latch 134 is linearly (in this embodiment vertically)movable to release the lever 132. Note for example FIG. 27, showing theengagement of the latch 134 with the lever 132. A locking point 136 isthe point at which a lever locking surface 139 of the lever 132 engageswith the latch locking surface 138 of the latch 134. The latch 134includes a magnet 135 fixed therein. Because the latch 134 can movevertically, attraction from above can cause the magnet 135 to pull thelatch 134 in the vertically upward direction to release the lever 132,allowing it to pivot as explained above. When the rotor hub 127 isrotated in the counterclockwise direction to reset the releasemechanism, for example a spring, as with the embodiment of FIG. 12,causes the lever 132 to pivot clockwise and engage an angle surface 140to push the latch 134 upward to allow the lever 130 to return to theposition of FIG. 27 and re-latch. A steel pin 137 is attracted to themagnet 135, and thus helps to hold the latch 134 in the engaged positionwith the lever 132.

Turning back to FIG. 23, a ball 41 is illustrated in a position after ithas fallen from its pedestal and moves slightly downward so as to beginthe clockwise movement of the flapper 148 about a pivot 149. In otherwords, after, for example, a seismic event has caused the ball 41 tofall off its pedestal, the ball has fallen toward the right to cause achange in the force balance about pivot 149. This causes the flapper 148as a whole to rotate clockwise. With this movement, a magnet or steelmember 144 as part of the flapper 148 is moved to the position asillustrated in FIG. 24. In the position shown in FIG. 24, the magnet 144attracts the magnet 135 of the latch 134, causing the latch 134 to slideupwardly and away from the lever 132. The latch 134 slides by way oflatch guides 134 a (perhaps most easily appreciated from FIG. 28). Theupward sliding movement of the latch 134, as noted above, causes thelatch locking surface 138 and the lever locking surface 139 to disengagefrom each other. The force at 153 causes the locking lever 180 to pushthe lever 132 in the counterclockwise direction as shown in FIG. 24.This allows the rotor hub 127 as a whole to be released and to move inthe clockwise direction. After, for example, the seismic disturbance isover and it has been determined that the release mechanism may be reset,the rotor hub 127 is rotated counter-clockwise to its original position,also causing the flapper 148 to rotate back to its set position andresetting the ball 41 on its pedestal, as will be explained in moredetail below.

The flapper 148 is further illustrated in FIG. 25. Reference number 150indicates the pedestal in this embodiment. In this embodiment, acounterweight 142 acts as a weight on one side about the pivot point149, while the ball 41, on its pedestal 150, is already on the otherside of the pivot lever 149. A sloped surface 151 is provided adjacentthe pedestal so that, when the ball 41 falls from the pedestal 150, theball falls down the sloping surface 159 to a point where its weight willovercome the weight of the counterweight 142 to cause rotation of theflapper 148.

The retaining wall 152, which is only partially illustrated in FIG. 25,surrounds the area in which the ball 41 is contained. It is constructedso that there is sufficient space for the ball 41 to come completely offof the pedestal 150; in other words, sufficient space is provided to theside of pedestal 150 so that if the ball 41 only partially leaves thepedestal 150, it will not cause the ball to be deflected to the slopingsurface 151 to cause triggering.

Upon actuation, as the rotor hub 127 rotates from the position of FIG.24, a flapper cam follower 148 a on the flapper 148 encounters a flappercam 148 b on the rotor hub 127. Note for example FIG. 29, illustratingthe flapper cam on a front rotor hub part 127 a. This causes the flapperto be returned toward the position illustrated in FIG. 23. As the rotorhub 127 is rotated counterclockwise to reset the rotor hub 127 in thelocked position, the flapper cam follower 148 a rides on the flapper cam148 b to maintain this position, and as can be seen from FIG. 29, theflapper cam 148 b increases in radius to cause a bump of the flapper camfollower 148 a to ensure sufficient tilt of the flapper 148 to cause theball 41 to reset on the pedestal 150. Further, in the set or resetposition (illustrated in FIG. 23, for example, except for the positionof the ball 41) the left-hand part of the flapper 148 engages the rotorhub 127 to maintain its position. Note point 155 at the position of thecounterweight 142 as shown in FIG. 23. This point 155 engages with asurface of the rotor 127 so that the flapper 148 rests on the outer partof the hub, ensuring the reset position. This ensures the proper resetposition in which the sloped surface 151 of the flapper 148 in factslopes downward, ensuring that when a sufficient seismic activity, forexample, causes the inertia ball 41 to leave its pedestal, it will rollin the proper direction to cause rotation of the flapper 148.

It is noted that the magnet 144 of the flapper 148 may simply be a steelplate to be attracted to the magnet 135 of the latch 134. Obviously theattraction between magnet 135 and steel plate 144 is greater than theattraction between steel pin 137 and magnet 135, and sufficient toensure vertically upward movement of the latch 134 to release the lever132.

As noted above, the latch guides 134 a are better illustrated by FIG.28, the view taken from above. Providing corresponding guides andprojections on either sides, in different number (one set 134 a shown onthe lower side and two sets 134 a shown on the upper side) ensures thatduring assembly, the latch 134 will be turned the correct way wheninserted into the rotor hub 127.

A particular advantage of the arrangement of the embodiment of FIGS.23-29 is that it permits a large number of the components to be moldedfrom plastic. That is, this arrangement requires less strict tolerancesthan some of the other embodiments discussed herein, allowing for thecomponents to be less precisely made, for example, by molding fromplastic. In particular, the vertically sliding latch 134 for the lever132 allows for less stringent tolerances than might be required with thelatches of the previously-described embodiments.

The release mechanism according to the present invention has beendescribed above particularly with respect to the activation of theclosure of a valve upon detection of seismic activity, for example.However, the release mechanism according to the present invention can beapplied in other contexts. For example, the rotor hub 27 or 127 of theabove-described embodiments could be employed together with the cable 23to actuate the opening of a circuit breaker to shutoff electricity uponthe detection of, for example, a seismic event. FIGS. 30 and 31schematically illustrate how this might be accomplished.

In FIGS. 30 and 31, reference number 222 represents a switch or circuitbreaker having a movable component such as a handle. FIG. 31 illustratesthe “set” position in which the rotor hub is held in locked position.FIG. 30 represents the position in which the release mechanism willtrigger 227 has been actuated. A spring 228, upon actuation, forces theopening, for example, of the switch or circuit breaker 222 by the forceof the spring 228 being sufficient to pull the lever or handle from theposition of FIG. 31 to the position of FIG. 30.

Also illustrated in the figures, as part of the cable mechanism, is atolerance spring 223. The tolerance spring 223 is a spring which isstronger than the spring 228. Upon actuation from the position of FIG.31, the cable, with the spring 223, has been released by the trigger227. Thus, neither the cable nor the spring 223 prevent the spring 228from pulling the lever toward the left hand position of FIG. 30.However, upon reset from the position of FIG. 30, rotation of the rotorhub, for example, in the counterclockwise direction causes the cable tobe pulled in toward the trigger 227 to cause the movement of the levertoward the right hand side as illustrated in FIG. 31. Because the spring223 is stronger than the spring 228, the cable still overcomes the forceof the spring 228 biasing the lever toward the left hand side.

However, as the lever reaches its end position as shown in FIG. 31, asits re-set position, at the same time, the rotor hub 127, for example isreaching its own re-set position. Because the rotor hub 127 may have torotate slightly past the locked position to ensure that the rotor hub127 is properly reset, the spring 223 allows for slight continuedmovement of the rotor hub 127 in the counterclockwise direction, withoutfurther movement of the lever of the switch 222.

While the tolerance spring 223 may not be needed as part of the cablemechanism connecting the trigger 227 to the lever of the switch 222, itspresence is useful, because it allows for manufacturing to be madeeasier. That is, less stringent tolerances are required with thepresence of the tolerance spring 223.

FIGS. 32-35 illustrate another alternative structure of the valveassembly. This valve assembly can form a safety valve usable in the samemanner as described above in supply plumbing for supplying a fluidmedium to a point of use structure, and is usable with a mechanicalactuator as described in the previous embodiments. A cable 328 asillustrated in FIG. 34, for example can correspond to the cable 23 asdescribed above for engagement with the mechanical actuator.

A valve housing 312 has an inlet 310 and an outlet 310 a. The housing312 is sealed off by a cap 330. In FIG. 32, the valve is shown in theclosed position with an outlet sealed off by a rubber-like stopper 316engaging with a valve seat 313 formed in the housing 312.

A spring 323 applies a compression load sufficient to form a good leaktight seal against seat 313 and, at the same time, form and effect aseal around the cable 328 by compressing an o-ring around the cable (seeFIG. 35; further described below).

A bypass is provided in order to allow for easy reset of the valve underhigh pressure. When the valve is in the off position, the bypass issealed off by the compression load supplied by the spring. The springcauses a bypass piston 320, specifically, to effect a seal against abypass seat 318.

The valve assembly has a plunger 322 which holds a stopper base 319 inplace, which in turn has the stopper 316 attached thereto. The stopper316 is held in place by a stopper holder 311 which has a bypass orifice317. The plunger 322 assembly is guided by a plunger guide 330 a formedwithin cap 330, as seen in FIG. 32. The stopper base 319 is allowed tomove and is held in place by a stopper guide 319 a. The other end of theplunger 322 assembly is guided by the stopper base 319 and the stopperbase guide 319 a.

Noting initially FIG. 33, when the cable 328 is pulled to open thevalve, the bypass piston 320 will initially move away from the bypassseat 318, allowing fluid to pass through the bypass orifice 317 (thedirection of fluid flow is illustrated by the arrows in FIG. 33). Abypass clearance 317 a is provided around the bypass piston to allow thefluid to flow around the bypass piston 320. The force that is thenrequired to open the piston will equal the spring load plus the pressuredifferential of the bypass piston against the bypass seat. The bypasspiston 320 will open with less force than that of the stopper 316 thatis sealed against seat 313, because the cross sectional area of thevalve seat 313 is much larger than that of the bypass seat 318.

Noting FIG. 34, as the bypass 317 allows the pressure differential atthe stopper to equal that of the spring load, the plunger assembly willthen open the valve.

FIG. 35 shows a cap 342 sealing the housing 312 off from the outside byway of a cap seal 329 and a cable seal 325. Spring 323 engages a springguide 324, which in turn compresses the cable seal 325, which is locatedin a cable seal housing 327, against the cable 328. As can be seen fromFIG. 35, the cap seal 329 is in turn compressed between the cap 342 andthe cable seal housing 327.

The valve assembly of FIGS. 32-35 has the advantage allowing for easyresetting of the valve while providing a good seal. The spring helps toseal the valve seat 313, the bypass seat 318 and the housing cap 330.The bypass orifice 317 has a much lower pressure differential toovercome during the resetting of the valve to the open position. Forexample, if the valve seat is 2 inches in diameter, the cross sectionalarea would be approximately 3.14 square inches. If the pressuredifferential were 100 PSI on the inlet side of the stopper, then theforce necessary to reset the valve would be 314 pounds of force. If thebypass seal has a cross sectional area of ⅛ inch, the cross sectionalarea would be 0.05 square inches; thus at 100 PSI, the force necessaryto open the bypass would be 5 PSI. The opening of the bypass then allowsthe pressure differential to equalize so that the valve can be fullyreset without the need for applying a much larger force at higherpressures. Such feature enables the valve to work with higher-pressurefluids, such as water. The sealing to the atmosphere around the cable,which is a smaller diameter than the plunger, also reduces the frictionand makes it easier to achieve a low leakage rate.

FIG. 36 is a sectional view of a valve assembly that could replace aby-pass tee in the gas system. It is composed of a valve housing 410having an inlet 411 and outlet 412. The inlet is plumbed with a pipefitting 413 coming from the gas meter that is shown in FIG. 38. Theoutlet is plumbed with the pipe fitting 414 that goes into the house asshown in FIG. 38. The valve member 416 is shown in the open position.The valve housing has an opening 415 with a pipe plug 426 a. This pipeplug can be removed so it can be used with a bypass method described inU.S. Pat. No. 6,705,340. This valve arrangement would allow the by-passmethod of keeping the gas on while replacing the gas meter. The by-passwould be used when the valve is in the open position. This arrangementwould be very easy to install because almost all gas systems have aby-pass tee that is used by the gas utility.

FIG. 37 is a sectional view of the valve assembly showing it in theclosed position. The valve member 416 is sealed against a seat 416. Aspring load holds the valve member in place and is stronger the gaspressure so it stays in the closed position.

FIG. 38 is described in U.S. Pat. No. 6,705,340 showing a gas system andthe by-pass tee 427 and pipe plug 426.

The advantage of this arrangement is to allow for easy installation byjust replacing the by-pass tee with this valve arrangement. It wouldallow the gas utility to use their by-pass method to service the gasmeter.

The invention discussed above presents, including with respect to thevarious alternatives, a new approach to ensuring the inexpensive andreliable installation of safety valves at point of use structures. Theactuator according to the present invention provides a standardizedtrigger which can work with valves of different sizes, for example from¾ inch valves to 6 inch valves. The actuator and trigger is easilymounted on the point of use structure without requiring any bracing. Theremotely positioned valve, provided in the supply pipes or plumbing, isquickly and easily installed without requiring separate leveling orother bracing to the structure. The valve is easily reset withoutrequiring separate tools. Further, a separate manual shutoff is providedwhich can also be adapted to remote control in response to, for example,a heat sensor for fire detection.

Various modifications of the above-described embodiments will beapparent to those of ordinary skill in the art. Any and all suchmodifications should be considered within the scope of the presentinvention as defined by the appended claims.

1. A valve arrangement comprising: a safety valve located in supplyplumbing for supplying a fluid medium to a point of use structure; and amechanical actuator to actuate said safety valve, said mechanicalactuator being mechanically connected to said safety valve and locatedremotely from said safety valve. 2-30. (canceled)
 31. A gate valve formounting between pipe ends, comprising: a gate valve housing having afluid flow passage for connection with the pipe ends and gate movablebetween an open position in which the fluid flow passage is open and aclosed position in which said two supply pipes are closed off from eachother; and first and second connection arrangements for connecting saidgate valve housing with the pipe ends to communicate said fluid flowpassage with the pipe ends; wherein at least one of said connectionarrangements comprises a union nut threaded to said gate valve housing,an insert engaging said union nut and threads on the insert for engagingone of the pipe ends. 32-35. (canceled)
 36. A release mechanism,comprising: a rotor rotatably mounted in a rotor housing; a first leverpivotally mounted on said rotor to be pivotal between a locking positionand a release state; a second lever pivotally mounted on said rotor tobe pivotal between a latched position and a release state, wherein saidfirst lever engages said second lever to hold said first lever in saidlocking position when said second lever is in said latched position; anda latch operable to hold said second lever in said latched position andto release said second lever. 37-65. (canceled)